Growing up with the OT, it was very safe to say that green and blue were good colors, and red was the evil color. Do these still hold ground today? Maybe. In a series about good vs. evil, the colors of lightsabers became a sort of symbolism. The OT holds this true, and even Ep 1 holds this into regard. But in Ep 2, it all starts going to Hell. It's confusing, but it all makes sence when you start thinking about it.

As you all (should) know, the color of the lightsaber depends on what color crystal is inserted into the hilt. These crystals grow in caves, and part of Jedi training includes building your own lightsaber. What stops a Jedi from putting a red crystal in their lightsaber? History.

My theory on how red lightsabers came to repreent the Sith is an easy to follow one . Before the Sith formed under Darth Bane, Jedi likely used red sabers all the time. However, during the Jedi Civil War, many people were unable to tell the Jedi from the Sith because the two groups were actually very similar in nature. An easy way to identify a Sith from a Jedi could have been the red saber. The Sith probably adopted it as a uniform of their own to tell themselves apart from the Jedi. They chose red because it's the color of blood and fire, and it's capable of striking fear into he hearts of their opponents. Since then, a Jedi using a red saber was probably looked down upon. What once could have been a noble color of lightsaber had been turned to a symbol of evil.

With that said, that leaves every other possible color to the Jedi. A common theory is that blue represents an inexperienced Jedi and a green one represents a Jedi Master. This is proved wrong in both the OT and the PT. In the OT, if we were just looking at Luke, this theory might hold water. However, Obi-Wan is obviously a Jedi Master, yet he uses a blue saber. In the PT, we see a group of young padawans training with Yoda, all with mixed lightsabers; blue and green. The padawans with green lighsabers are obviously not Jedi Masters. And also, if green symbolized Jedi Mastery, then why are devoted Jedi Masters such as Plo Koon, Ki Adi Mundi, and Shaak Ti all using blue sabers? I believe that blue and green sabers are not symbols of experience and power with the force, but symbols of their focus. Anakin and Obi-Wan are powerful Jedi, but their focus is on lighsaber combat. This is probably what the blue saber signifies. The green lightsaber probably means that the user is well bonded with the force. Sorry Yoda fans, but Yoda puts far more focus on using his mind to control the force than in his lightsaber combat. Face it, Yoda couldn't beat Palps in a saber fight if his life depended on it. Yoda used not his lightsaber to it's full potential, but his ability to control the force. To put it short and simple, blue means a Jedi who focuses on combat and a green lightsaber is for a Jedi who focuses on the force. Mace Windu is truly gifted Jedi Master in both aspects and is truly the only one who focuses and masters both equally. He's a diplomat who only uses his lightsaber when he absolutely has to. When he does, he's the best saber fighter the galaxy has ever seen. Thus, that is probably why he is the only one with a purple saber.

Another very simple thing I must clear up. Why did Darth Vader use a blue lightsaber to fight Obi-Wan on Mustafar and not a red one? After all, he was a Sith, wasn't he? What did you want him to do? Take a break from slaughtering Jedi and make a new lightsaber? He had a blue lightsaber even though his true affiliation with the force usually means he is supposed to be using a red saber. He had to make due and wait until he had time to make a new one. The same goes for Luke. He was a green waiting to be unleashed, bur he was using his father's lightsaber which happened to be blue. Again, he had to make due until it was time for him to make a new lightsaber. Just like the real world, sometimes we just have to take what life gives us and make the best. Another example, Obi-Wan finished off Darth Maul with a green saber even though his focus would classify him a blue. Even if your personality screams, "Blue Lightsaber!" and you happen to be using a green one that isn't your's, you jsut have to make due. Don't let these switches confuse you.

In conclusion, there is viable reason for the way lightsabers are. They help classify a Jedi (or a Sith) so to speak. Either that, or they just like the color. What do you think?